The conformations of oligosaccharides related to the ABH and Lewis human blood group determinants

Abstract

Nuclear magnetic resonance properties are shown to be in good accord with those that are expected for synthetic oligosaccharides in the conformations which are predicted by hard-sphere molecular modelling and taking into consideration the important contribution by the exo-anomeric effect. The studies involve first a comparison of the β D Gal(1 → 3)β D GlcNAc (Type 1) and β D Gal(1 → 4)β D GlcNAc (Type 2) disaccharide structures based mainly on 13 Cmr and then an examination of the relationships between the calculated conformations and 1 Hmr and 13 Cmr parameters for human blood group determinants which are derived from the Type 1 core disaccharide. Among the structures examined are the di-, tri-, and tetrasaccharides for the ABH and Lewis antigenic determinants. Certain immunological–conformational relationships are noted.